Author Topic: 555 timer confusion (Read 5854 times)

osnap · « **on:** March 04, 2007, 01:34:42 PM »

hi all,

I've been reading that you can make some cool simple circuits using 555 timers. I looked and I saw that radioshack had one, so I think I'm going to buy some -- but I'm confused I know it doesn't need to be programmed, so, what would be needed to make a simple flashing LED circuit or something?

thanks, any help is greatly appreciated

555 timer chip guy · « **Reply #1 on:** March 04, 2007, 07:52:51 PM »

Here are some cool projects one is an astable oscillator (if you attach an LED to the output it will flash) and then if you get a 556 duel trimer or 2 555 timers you can make a light seeking robot with the uther schematic

osnap · « **Reply #2 on:** March 04, 2007, 07:54:49 PM »

Woa... uh.. could you just explain the schematic a bit?
I already don't understand 555 timers much as it is lol

gamefreak · « **Reply #3 on:** March 04, 2007, 08:17:48 PM »

well those schematics helped me figure out my 555 timer, but they arent very.... pin friendly

http://www.uoguelph.ca/~antoon/gadgets/555/555.html, has the pin positions so if you base off both of the drawings then you can get a working LED flasher with adjustable speed

osnap · « **Reply #4 on:** March 04, 2007, 08:19:09 PM »

how is the speed adjusted?

555 timer chip guy · « **Reply #5 on:** March 04, 2007, 08:22:16 PM »

OK it is really quite simple their are two different basic types of circuits for the 555 one is astable that is gust a continues pulse. Here is an example.then there is monostable witch is triggered and last for a specific amount of time. for more info got to www.kpsec.freeuk.com/555timer.htm this is were I learned every thing I now about the 555 and 556 timers.

555 timer chip guy · « **Reply #6 on:** March 04, 2007, 08:24:01 PM »

Quote from: osnap on March 04, 2007, 08:19:09 PM

how is the speed adjusted?

it is adjusted with the 50k pot

osnap · « **Reply #7 on:** March 04, 2007, 08:27:20 PM »

hmm okay, I guess I just need to read more then before I try and work one of these

Brandon121233 · « **Reply #8 on:** March 04, 2007, 10:16:14 PM »

If you really want to understand them the BEST book is by Forest Mims the 3rd called Timer, Op Amp & Optoelectronic Circuits & Projects, it has detailed schematics and explanations for everthing you would want to know.

Hal9000 · « **Reply #9 on:** March 05, 2007, 11:36:44 AM »

This is possibly the ultimate book for you:

http://www.amazon.co.uk/Integrated-Circuit-555-Projects-BP/dp/0859340473/ref=sr_1_1/203-6935087-2798348?ie=UTF8&s=books&qid=1173116172&sr=1-1

It reads like an old uncle who smells of old spice.

robot321 · « **Reply #10 on:** March 05, 2007, 02:59:20 PM »

I can post a blinking LED circuit if you need it.

osnap · « **Reply #11 on:** March 05, 2007, 07:02:19 PM »

Thanks for those two books

And ya, robot321, I'd like that very much

I found this circuit that I want to try:
http://www.doctronics.co.uk/images/555_10.gif

but I'm confused about what connects where -- I couldn't find a shot from the bottom, lol

trigger · « **Reply #12 on:** March 05, 2007, 07:05:03 PM »

Quote from: osnap on March 05, 2007, 07:02:19 PM

but I'm confused about what connects where -- I couldn't find a shot from the bottom, lol

It's a breadboard pic--no need for a shot from the bottom.

osnap · « **Reply #13 on:** March 05, 2007, 08:11:52 PM »

oh... so it is

rofl thanks

osnap · « **Reply #14 on:** March 05, 2007, 11:35:55 PM »

Hey, if wanted to make this, does this mean that the two output wires are my + and -, that I would connect to a LED if I wanted to have it flash every 120 seconds?

also, on the left, is that the + and - from like 9v battery?

robot321 · « **Reply #15 on:** March 06, 2007, 10:16:13 AM »

Log-in to view attached 555-timer circuit

ed1380 · « **Reply #16 on:** March 06, 2007, 05:27:40 PM »

You could put a pot where resitor one is to regulate how fast is flashes right?

osnap · « **Reply #17 on:** March 06, 2007, 06:34:19 PM »

Thanks, Robot321. (Instead of that 1 6v, 4 AAs would work, right? lol

robot321 · « **Reply #18 on:** March 06, 2007, 07:12:30 PM »

osnap: yes 1.5vx4 =6v

ed1380: yes a pot would do nicely

osnap · « **Reply #19 on:** March 06, 2007, 07:15:03 PM »

what is a pot? lol

robot321 · « **Reply #20 on:** March 06, 2007, 07:18:03 PM »

pot short for potentiometer are adjustable resistors.

osnap · « **Reply #21 on:** March 06, 2007, 08:08:10 PM »

cool -- i think i'll try making what you posted.
(is a breadboard worth investing into?)

555 timer chip guy · « **Reply #22 on:** March 08, 2007, 06:02:07 PM »

Quote from: osnap on March 06, 2007, 08:08:10 PM

cool -- i think i'll try making what you posted.
(is a breadboard worth investing into?)

A bread board is the most important prototyping tool you will ever use.

sdk32285 · « **Reply #23 on:** March 08, 2007, 09:50:58 PM »

Here's a useful link
it can solve for resistance(R1 and R2), capacitance, frequency, time-on, and time off.

http://noisybox.net/electronics/555.php
(you need to enter 3 of 4 values)

osnap · « **Reply #24 on:** March 09, 2007, 06:23:01 PM »

Thanks

last thing -- i bought a breadboard - am i supposed to remove the paper on the back so the little metal peices show?

Eco19R · « **Reply #25 on:** March 09, 2007, 06:25:36 PM »

Leave it on.

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Author Topic: 555 timer confusion (Read 5854 times)

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